I. Field of the Invention
The present invention relates to a safety arrangement for medical procedures. More particularly, the present invention involves a method and apparatus for preventing air embolisms during medical procedures involving the access of anatomical cavities.
II. Brief Description of the Related Art
Introducing instruments into anatomical cavities is commonplace in a wide variety of medical procedures. In cardiac surgery, cannulas are introduced into the various chambers of the heart to re-route blood within and/or outside the heart. Intravascular devices, such as catheters and guidewires, are commonly introduced into the vascular system of a patient in cardiology procedures. Accessing major anatomical cavities, such as the thoracic cavity, may be accomplished through the use of such instruments as trocars. In each instance, the introduction of air into the anatomical cavity being accessed is undesirable in that it can present the possibility of air embolism formation. In the circulatory system, for example, air embolisms pose the danger of a stroke to the patient. One cause for the introduction of air into the cavity being accessed is when the pressure within the cavity is sufficiently lower than outside the cavity. When such a negative pressure differential exists inside the cavity, the resulting suction force can draw air from outside the cavity into the cavity.
The present invention is directed at overcoming the above-identified problem of air being drawn into an anatomical cavity due to a negative pressure differential developing therein.
One aspect of the present invention involves providing a method of preventing air embolisms. The method comprises the steps of: (a) providing a fluid source in communication with an aperture extending into an anatomical cavity; and (b) delivering fluid from the fluid source into the anatomical cavity when a condition of negative pressure exists in the anatomical cavity.
One embodiment of the method includes the steps of providing a fluid delivery conduit in communication with the aperture of the anatomical cavity, and coupling the fluid source to the fluid delivery conduit to deliver fluid into the anatomical cavity.
One embodiment of the method includes the steps of providing the fluid delivery conduit with a first opening and a second opening, and providing a sealing member across the first opening of the fluid delivery conduit.
One embodiment of the method includes the steps of providing an aperture in the sealing member, introducing an instrument through the aperture in the sealing member, and extending the instrument into the anatomical cavity.
One embodiment of the method includes the steps of providing a second sealing member across the second opening of the fluid delivery conduit, providing an aperture in the second sealing member, passing the instrument through the aperture in the sealing member, and extending the instrument into the anatomical cavity.
One embodiment of the method includes the step of positioning the fluid delivery conduit such that the fluid delivery conduit extends through the aperture into the anatomical cavity.
One embodiment of the method includes the step of positioning the fluid delivery conduit such that the fluid delivery conduit does not extend through the aperture into the anatomical cavity.
One embodiment of the method includes the step of controlling the delivery of fluid from the fluid source based on a parameter indicative of a negative pressure within the anatomical cavity.
In one embodiment of the method, the parameter may comprise one of pressure within the anatomical cavity, pressure outside the anatomical cavity, flow rate of fluid being delivered into the anatomical cavity, oxygen content of fluid within the anatomical cavity, and oxygen content of fluid being removed from the anatomical cavity.
One embodiment of the method includes the step of controlling the delivery of fluid from the fluid source based on a parameter indicative of a negative pressure within the anatomical cavity. Also provided is the step of selecting the parameter from at least one of pressure within the anatomical cavity, pressure within the fluid delivery conduit, flow rate of fluid through the fluid delivery conduit, oxygen content of fluid within the anatomical cavity, and oxygen content of fluid being removed from the anatomical cavity.
In another aspect of the present invention, an apparatus for preventing air embolisms is provided. The apparatus comprises a fluid source in communication with an aperture extending into an anatomical cavity such that fluid may be delivered into the anatomical cavity when a condition of negative pressure exists in the anatomical cavity.
One embodiment of the apparatus includes a fluid delivery conduit in communication with the aperture. The fluid delivery conduit is coupled to the fluid source to deliver fluid into the anatomical cavity.
In one embodiment of the apparatus, the fluid delivery conduit includes a first opening and a second opening, and a sealing member is disposed across the first opening of the fluid delivery conduit.
In one embodiment of the apparatus, the sealing member includes an aperture for receiving an instrument therethrough.
One embodiment of the apparatus includes a second sealing member disposed across the second opening of the fluid delivery conduit. The second sealing member includes an aperture for receiving the instrument therethrough.
In one embodiment of the apparatus, the fluid delivery conduit is positioned to extend into the anatomical cavity.
In one embodiment of the apparatus, the fluid delivery conduit is positioned such that the fluid delivery conduit does not extend into the anatomical cavity.
One embodiment of the apparatus includes a controller for controlling the delivery of fluid from the fluid source based on a parameter indicative of a negative pressure within the anatomical cavity.
In one embodiment of the apparatus, the parameter comprises one of pressure within the anatomical cavity, pressure outside the anatomical cavity, flow rate of fluid being delivered into the anatomical cavity, oxygen content of fluid within the anatomical cavity, and oxygen content of fluid being removed from the anatomical cavity.
One embodiment of the apparatus includes a controller for controlling the delivery of fluid from the fluid source based on a parameter indicative of a negative pressure within the anatomical cavity.
In one embodiment of the apparatus, the controller includes a sensor for sensing at least one of the parameters.
In one embodiment of the apparatus, the parameter comprises at least one of pressure within the anatomical cavity, pressure within the fluid delivery conduit, flow rate of fluid through the fluid delivery conduit, oxygen content of fluid within the anatomical cavity, and oxygen content of fluid being removed from the anatomical cavity.
In a still further aspect of the present invention, a system is provided for preventing air embolisms during medical procedures involving introducing an instrument into an anatomical cavity. The system comprises a fluid delivery conduit in communication with an aperture extending into the anatomical cavity. A fluid source is coupled to the fluid delivery device for delivering fluid into the anatomical cavity when a condition of negative pressure exists within the anatomical cavity.
One embodiment of the system includes a controller for controlling the pressure within the anatomical cavity.
In one embodiment of the system, the controller includes a pump for selectively delivering fluid into the anatomical cavity in response to the condition of negative pressure within the anatomical cavity.
In one embodiment of the system, the pump controls the flow of fluid from the fluid source.
In one embodiment of the system, the pump controls the flow of fluid through a cannula extending into the anatomical cavity.
One embodiment of the system includes a sensor for sensing a parameter indicative of a negative pressure within the anatomical cavity.
In one embodiment of the system, the parameter comprises at least one of pressure within the anatomical cavity, pressure within the fluid delivery conduit, flow rate of fluid through the fluid delivery conduit, oxygen content of fluid within the anatomical cavity, and oxygen content of fluid being removed from the anatomical cavity.
In one embodiment of the system, the sensor comprises at least one of a pressure sensor, a flow sensor, an oxygen sensor, a motor speed sensor, a pump output sensor, and a strain gauge.
Another aspect of the present invention involves providing a method of preventing air embolisms comprising the step of reducing or eliminating a condition of negative pressure within an anatomical cavity such that air will not be drawn through an aperture extending into the anatomical cavity.
One embodiment of the method includes the step of delivering fluid into the anatomical cavity when the condition of negative pressure occurs within the anatomical cavity.
One embodiment of the method includes the step of the step of delivering the fluid through the use of a fluid source in communication with the anatomical cavity.
In one embodiment of the method, the fluid source delivers the fluid into the anatomical cavity through a fluid delivery conduit extending through the aperture into the anatomical cavity.
One embodiment of the method includes the step of controlling the withdrawal of fluid from the anatomical cavity to reduce or eliminate the negative pressure.
One embodiment of the method includes the step of stopping the withdrawal of fluid from the anatomical cavity to reduce or eliminate the negative pressure.
One embodiment of the method includes the step of varying withdrawal of fluid from the anatomical cavity to reduce or eliminate the negative pressure.
One embodiment of the method includes the step of controlling the reduction or elimination of the negative pressure based on a parameter indicative of a negative pressure within the anatomical cavity.